Throttle-valve



(No Model.)

J. J. TQNKIN. THROTTLE VALVE.

atented Feb. 8 1887.

may

' WITNESSES:

1 0 T N V N ATTORNEYS NrrED STATES TH BOTTLE-VALVE.

SPECIFICATION forming part of Letters Patent No. 357,511, dated February 8, 1887.

Application filed October 16, 1886.

To all whom it may concern:

Be known that I, J omv J AY TONKIN, of Oswego, in the county of Oswego, in the State of New York, have invented new-and useful Improvements in Throttle-Valves for Steam-Engines, of which the following, taken in connection with the accompanying drawings, is a full, clear, and exact description.

This invention relates to the class of throttlevalves which are located inside of the steamchest and mounted on the main valve; and the invention consists in an improved construction and combination of parts, whereby the throttle-walve is nearly or quite steam balanced and the friction thereof is reduced to a minimum, all as hereinafter more fully described, and specifically set forth in the claims.

In the accompanying drawings, Figure l is a longitudinal vertical section of my invention as applied to a slide-valve of an engine; and Figs. Zand 3are transverse sections, respectively, on lines so a: and g yin Fig. 1. 1

Similar letters of reference indicate corresponding parts.

A represents the top port-ion of a horizontal steam-cylinder provided with the usual valve-seat, B, steam-ports O O, and exhaustport E; and H denotes the steam-chest provided with a port, F, through which it re ceives steam from the steam-pipe, which is connected to the steam-chest in the usual and well-known manner, and therefore not necessary to be here illustrated.

V represents the valve of the engine,which valve is of the class designated slide-valves, and arranged to be reciprocated upon the valve-seat B in the usual manner.

WVhen the'steam-inlet port F is in the side of the steam-chest, as shown in Fig. 2 of the drawings, I provide the valve V with a 1011- gitudinal breast, I, bearing against a suitable smooth face, I, on the side of the interior of the steam-chest opposite the port F, and thereby enable the said valve to better resist the side pressure received from the steam entering through the said port.

The valve V, I make of awidth to span the steam-chest, and of a length to make its ends extend beyond the steam ports 0 C, and the under side of the central portion thereof I Serial to. 216,390. (No model.)

provide with the usual exhaust'cavity, a, communicating directly with the exhaust-port E of the cylinder.

1) I) represent live-steam passages formedinside of the valveV, and extending lengthwise thecentral portion thereof above the exhaustcavity a and down through the end portions of the valve,and having their ends in the face of the valve in proper positions in relation to the steam-ports O G of the cylinder, so as to bring them alternately in coincidence with.

the same during the movements of the valve, in the usual manner.

The top of the valve V, I provide with a supplemental valve-seat, c, which is extended the entire length of said valve and is concave and of semicircular o'r segmental form in crosssection, and upon this valve seat 0, I mount the throttle-valve D, which is of cylindrical form and hollow, the cavity thereof being concentric with the exterior. Said valve is to receive oscillatory motion from the usual spindle of a centrifugal steam-governor, which may be of any suitable and well-known form, and therefore requires no illustration in this case.

The shaft or stem of the throttle-valve projects through a stuffing-box on the steanrchest, and the means for connecting said shaft or stem with the governor-spindle can readily be devised by the skill of an engineer desiring to avail himself of my invention.

It will be observed that in the described construction and combination of the hollow cylindrical throttle-valve with the segmental or troughshaped supplemental valve-seat on the main valve only one-half or less than one: half of the surface of the throttle-valve is subjected to friction, and the valve is nearly or quite steam-balanced. a

The ends of the throttle-valve D are closed, and the side of said valve facing the valveseat 0 is providedwith discharge-ports f f, coinciding with similar ports, (I d, extending through the valve-seat and into the steampassages b b. The upper part of the valve D is provided with a steam inlet port, 6, by which it receives steam from the interior of the steam-chest. The ports d d and f f are arranged in such relative position as to cause them to coincide with each other, as shown in Fig. 2 of the drawings,when the governor is at rest, and thusthe steam with which the steamehest and throttle-valve D is charged has free entrance to the passages I) bin the valve V, which passages are therefore charged with live steam simultaneously with the steamchest. lVhen the engine is set in motion, the

live steam passes from the passages Z) Z) alteran engine, a slide-valve having both ends extending beyond the steam-ports of the cylinder and provided with an exhaust-passage at the center, and with internal steam-passages extending through the central portion of the valve over the exhaust-passage and through the ends at the side facing the valve-seat, a c011- cave supplemental valve-seat of semicircular form in cross-section on the aforesaid valve, ports in said supplemental valveseat communicating with the internal steam-passages of the slidevalve, and an oscillatory tubular or hollow throttle-valve of cylindrical form riding on the segmental seat and having a steamreceiving port and steam-discharge ports, which latter are through the side facing the supplemental valve-seat, substantially as described and shown.

2. The combination ofthe steam-chest having the steam-inlet port F in one side and a smooth face, 1, on the opposite side, and the valve spanning the steam-chest and provided with the breast l, bearing on the face 1, substantially as and for the purpose set forth.

In testimonywhereof I havehereunto signed my name and affixed my seal, in the presence of two attesting witnesses, at Oswego, in the county of Oswego, in the State of New York, this 12th day of October, 1886.

JOHN JAY TONKIN. 

